Devices are known for pre-treating and digitizing an analog signal for its use by a computer (French patents 2,565,746, 2,495,356 and 2,234,704; U.S. Pat. Nos. 4,101,072, 3,832,577, and 4,335,301); however in these devices, the pretreatment permitting extraction of the significant information is not parametrable, that is to say is definitely fixed without taking into account the specific characteristics of the analog signal, which brings about the impossibility of interpreting the information issuing from the treatment since the analog signal deviates from the norms for which the device has been provided. For example, in the case of a bar code, a noise greater than provided (caused particularly by a poor printing of the bars, of inadequate contrast, of poor quality members in the reader or the analog gathered string . . . ) prevents in these devices obtaining a useable binary signal. Moreover, in most of these devices, the pretreatment is carried out directly on the analog signal by a treatment of an analog nature, the binarization only taking place after leaving the treatment. One such treatment remains rustic and vitiates errors such that a non-negligible fraction of significant information contained in the analog signal is definitely lost, while the task of the computer is made more complex, since it must correct the errors introduced.
The present invention seeks to provide an improved process and apparatus permitting obtaining a parametrable binary signal representative of the significant component of an analog signal (the parameterization may in particular be assured in real time by the computer called upon to use the binary signal, as a function of the signal which it receives, in order to adapt the treatment to the characteristics of the analog signal).
Another object is to carry out a treatment of a numeric nature on a preliminarily digitized signal in order to avoid introduction of errors or loss of significant information, as is the case in the analogical treatments carried out heretofore.